Wacker Chemie Ag

Wacker-Chemie Gmbh

Manfred Meisenberger

Georg Loessel

Thomas K&ouml;hler

Richard Weidner

Volker Frey

Gerhard Staiger

Thomas Koehler

Wolfgang Wewers

Annemarie Huber

Thomas Koini

Reinhardt Mueller

Frank Betschinger

Marianne D Berthiaume

Erich Bildl

Wolfgang Ackermann

Georg Lößel

Georg Lössel

High hydroxyl-content organopolysiloxanes of low molecular weight are prepared in a continuous process by metering in alkoxysilanes and chlorosilanes in a weight proportion of 60:40 or more to a reaction mixture containing water and non-polar solvent, and continuously removing an organic phase containing organopolysiloxanes from the reaction mixture.

Method for producing SiOH-functional polysiloxanes

Organopolysiloxanes having an OH content of 3.0-10.0% by weight are produced in a continuous process in which silanes of the formula IRSiRX&#x2003;&#x2003;(I),in which with the proviso that 4&#x2212;m=n+o, and that in at least 30 mol % of the silanes of the general formula I, n&#x2260;0 und o&#x2260;0, water, and water-insoluble non-polar solvent are metered in continuously into a reactor to form a reaction mixture and the reaction mixture is continuously discharged from the reactor.

Organopolysiloxanes having an OH content of from 3.0-10.0 weight percent are continuously produced by continuously feeding chlorosilanes, alkoxysilanes, water, and nonpolar solvent essentially non-miscible in water, continuously discharging a reaction mixture containing organopolysiloxanes dissolved in a solvent phase, and optionally separating organopolysiloxanes from the solvent phase, wherein the chlorosilanes and alkoxysilanes are added in respective weight fractions of 95-60% and 5-40% based on the total weight of chlorosilanes and alkoxysilanes. The process does not employ and polar solvents, and produces products with improved flash points while minimizing complexity and expense of waste water treatment.

Silsesquisiloxanes are produced in high yield and purity in a minimal number of process steps by reacting quaternary ammonium silicates with disiloxanes in a precipitant liquid which causes the silsesquisiloxane product to be precipitated in high purity.

Method for producing organo-oligo silsesquioxanes

One-component, H-siloxane-containing addition-crosslinkable silicone resins, are prepared by charging a reactor with water and a solvent mixture of at least one aromatic solvent and at least one alkyl ester, adding a chlorosilane mixture containing an Si&#x2014;H functional silane and a silane bearing an unsaturated hydrosilylatable group with stirring, the temperature not being above 50&#xb0; C., separating an aqueous phase comprising a one-component, H-siloxane-containing addition-crosslinkable silicone resin, and washing the phase comprising the one-component, H-siloxane-containing addition-crosslinkable silicone resin in at least two washing steps to reduce residual HCl content, a final washing carried out using a 0.01%-1.0% strength aqueous solution of a base with a pH between 7.00-8.50, at a temperature of 20-50&#xb0; C.

Silicone resin coating for electronic components

A process for the preparation of organopolysiloxane resins, wherein a silaneRSiOR&#x2003;&#x2003;(I)or a hydrolyzate thereof, and a silaneSi(OR)&#x2003;&#x2003;(II)or a partial hydrolyzate thereof,

Process for the preparation of organopolysiloxane resin

Mixtures of volatile linear siloxanes

Process for preparing mixtures of linear organopolysiloxanes

The present invention relates to a process for preparing coating compositions which comprises condensing a mixture containing (A) at least one silicone resin containing Si-bonded alkoxy groups and, if desired, silanol groups and/or at least one silane and/or siloxane which contains Si-bonded alkoxy groups and, if desired, silanol groups to form a silicone resin, (B) a basic condensation catalyst in an amount sufficient to render this mixture basic, (C) optionally water and (D) optionally an organic solvent. The resultant coating compositions are preferably employed in the form of a solution, emulsion or dispersion.

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Burghausen, Germany

Manfred Meisenberger